Interleukin-6 expression by osteoblast-like MG63 cells challenged with four acrylic bone cements

Periprosthetic osteolysis is a major clinical problem in total hip and total knee arthroplasty and polymethylmethacrylate (PMMA) is a possible etiologic factor. Recently, increasing importance was ascribed to interleukin-6 (IL-6) as an agent favouring bone resorption. The aim of the present study was to investigate the role of bone cements on IL-6 production by MG63. The effect of four acrylic bone cements (Sulfix-60(R), CMW 1(R), CMW 2(R), and CMW 3(R)) on the protein release and mRNA expression of IL-6 in osteoblast-like cell line MG63 was examined using IL-1 beta (0.2 mug ml(-1)) as the positive control. The extracts in minimum essential medium (MEM) of the cements were tested, following l-h and 7-day curing. CMW 1(R) and CMW 2(R) significantly increased the IL-6 release into the culture media (p < 0.01). The cells incubated with Sulfix-60(R) and CMW 3(R) produced no significantly different levels of IL-6 than the basal production. A positive correlation was found between the concentration of IL-6 and the contents of benzoylperoxide (p = 0.0003) and barium sulphate (p < 0.0001). MG63 expressed IL-6 mRNA constitutively, as demonstrated by the positivity of the negative controls too. We conclude that CMW 1(R) and CMW 2(R) increase the production of IL-6 in MG63 cells. The response to Sulfix-60(R) and CMW 3(R) is not significantly greater than the negative control.